The danger with the current focus on viewability is that it has become a means unto itself – a target by which to measure success. However, while viewability measurement has an important role to play, it is primarily a measure of trading efficiency rather than an indicator of campaign effectiveness.

We conducted a major study with eye-tracking specialists Sticky and panel management company Research Now to better understand the role of viewability (the opportunity to see an ad) in the lifecycle of an ad exposure, alongside visual engagement (the likelihood that someone looks at it) and branding impact (what lasting impression it made). Around 4,000 surveys and 700 eye-tracking sessions enabled us to derive four important findings.

Learning #1: If you want any chance to be looked at, maximise exposure time

Exposure time needs to reach significant levels in order to attract visual engagement. This is not a revelatory finding, but its ratio may be – the average exposure time observed for ads to be looked at even fleetingly (<1 second) was 14 seconds.

Learning #2: Viewability is both great and not so great at predicting visual engagement

Viewability is very good at predicting if an ad has any chance to be looked at. The data showed that 90% of people don't look at ads that fall below the minimum IAB viewability guideline (50% in view for 1 second) while 0% looked at them for at least a second.

On the other hand, viewability is really bad at predicting how much attention an ad will get: 25% of viewable ads in the study received no attention at all, while 33% of users looked at the ad for less than a second (note that this is total accumulative time, rather than consecutive time).

More bad news: these stats include a high-impact skin format, which favourably influences overall visual engagement levels. When only observing standard formats, the incidence of ads receiving over a second's worth attention drops by eight percentage points.

This is significant, because the data shows that visual engagement drives branding impact: the more we look at advertising, the more likely we're to recall the brand, its assets and messages.

Learning #3: The right format can maximise effectiveness, but not beyond the boundaries set by creative execution

Comparing visual engagement levels across four formats and three categories (FMCG, automotive, sportswear) showed that relative attention levels were determined by formats, while absolute attention levels were driven by creative execution.

In other words, the relative performance of formats for visual engagement was stable. Across campaigns, the high-impact skin considerably outperformed all other tested formats, and the relationship between the standard formats also remained the same across campaigns (to simplify things – bigger seems to be better).

More importantly, however, was the observed difference of absolute attention levels a format received across campaigns. This suggests that choosing the right format can help maximise attention, however, a format's power will be limited by the boundaries set by campaign and creative execution.

Learning #4: Ad clutter is detrimental to visual engagement

Our research proved the considerable impact of ad clutter on visual engagement. In cluttered environments, an individual ad received on average 37% less visual engagement time and was 31% less frequently looked at. This translated into considerably worse performance on brand metrics for all tested IAB standard formats. Interestingly, the tested skin format did not perform worse in cluttered scenarios, a phenomenon that could be explained by the architectural structure of the format but which requires more research.

What can marketers and media agencies take from this?

Neuro-marketing tools such as webcam-based eye tracking have been on the rise but are still too often used without an appropriate understanding of what their output can actually reveal about campaign effectiveness. This needn't be the case. In fact, supported by research into their applicability to, and value for, robust ad effectiveness assessment, they can be hugely valuable.

Our research indicates that pre-testing users' visual engagement with a digital campaign and its formats / placements can add significant depth to the interpretation of in-flight viewability. Is format x likely to be looked at once it appears on the screen? Is there a placement on the media plan that performs slightly below par on viewability, but considerably outperforms the average when it comes to visual engagement? These insights can be gold for optimisation purposes.

This study reminds us that viewability measurement's remit is as an ad validation baseline, a tool that separates the certainly useless from the potentially useful. Industry bodies such as the IAB have constantly stressed that viewability measurement is not a panacea, doesn't equal effectiveness and has to be considered in context. It is on the industry players to finally put this into action.